As the authors of a recent systematic review (Cristea et al., 2017) and an accompanying editorial (Fonagy, Luyten, & Bateman, 2017) comment: Borderline Personality Disorder (BPD) is generally recognised as being a highly disruptive form of personality disorder, characterised by significant mental distress during times of crisis, as well as having a long-standing impact on social functioning that often responds poorly to support and treatment (Zanarini, Frankenburg, Reich, & Fitzmaurice, 2012).

BPD is often taken as being the archetypal representation for ‘personality disorder’ more generally, a group of disorders traditionally associated with feelings of therapeutic nihilism (Lewis & Appleby, 1988); although the development of psychotherapeutic techniques in the past 30 years has to some extent addressed this concern (Bateman & Fonagy, 2010; Linehan, 1987).

Systematic study into the efficacy of psychotherapy for individuals diagnosed with BPD is therefore important for its ability to clarify understanding, and identify areas for future research in this field.

Aims

The authors of the current review therefore sought to identify randomised control trials (RCTs) and to consider, through meta-analysis:

“…the efficacy of psychotherapies for BPD-relevant outcomes at post-test and, where possible, at follow-up.”

Borderline Personality Disorder can bring significant mental distress and result in poor social functioning.

Methods

The authors conducted a systematic search of electronic databases, using the terms ‘borderline personality’ and a restriction to limit identified studies to those labelled as ‘randomised trials.’

Inclusion criteria

Studies were included if they were identified as RCTs comparing psychotherapy with a control condition for adults diagnosed with BPD

Control groups could consist of ‘treatment as usual’ (TAU), or other treatments not specifically for BPD

Head-to-head comparisons between two therapies specifically designed for BPD were excluded

Medication use in both control and intervention arms was allowed, so long as this was not a structured intervention within the identified trial.

Appraisal for risk of bias

Risk of bias was appraised according to four domains from the Cochrane Collaboration Risk of Bias Tool

A ‘risk of bias’ score was computed with a study being awarded a point for each domain being deemed at ‘low’ risk of bias.

Study characteristics

Studies were identified as ‘stand alone’ (where comparison was made directly between the intervention and control group) and ‘add on’ (both groups received TAU with an additional intervention for the experimental group)

Therapy type was classified as:

DBT (Dialectical behaviour therapy)

Psychodynamic

CBT (Cognitive behavioural therapy)

Other

Control groups were classified as TAU, Supportive Therapy, ad hoc control (designed as part of the trial) and it was also noted whether control groups were ‘manualised’ or not

Meta-analysis

General psychopathology (measures of anxiety and depression in particular)

Differences between intervention and control groups were calculated at two points

Post-test

At later follow up (up to 2 years)

Effect sizes were calculated through the use of Hedges’ g

Heterogeneity (difference between study findings) was appraised.

Results

The authors identified 33 trials meeting their inclusion criteria

Only 28 of these trials reported sufficient data to allow the calculation of effect sizes. Authors of the missing 5 trials did not respond to requests for access to data

A total of 2,256 participants were included across the trials (1,169 intervention, 1,087 control)

12 trials included only women as participants

Treatment duration varied between 2.5 and 24 months with session numbers varying between 6 and 312.

Only 11 trials were rated as being at low risk of bias on 3 out of the 4 considered domains

Combining all trial types produced a moderate effect for BPD relevant outcomes (g=0.35 95% CI 0.20 to 0.50) at post-test with a moderate degree of heterogeneity to findings (48%)

No difference in treatment retention was identified between treatment and control groups

At follow up (up to 2 years) 2 deaths by suicide had occurred in the treatment group, versus 5 in the control group

Combining design types at follow up again produced a moderate effect in favour of psychotherapy (g=0.45 95% CI 0.15 to 0.75), heterogeneity was high for this finding (70%).

Subgroup analyses

DBT and psychodynamic therapy approaches were found to be effective versus control, CBT and other treatment types were not

Analysis of trials with a specifically developed (ad hoc) control group, manualised control intervention, low risk of bias (on at least 3 of 4 bias measures), or where the study team were directly involved in the control group treatment, all led to a loss in the statistical significance of the treatment effect.

Meta-regression analysis

The relationship between risk of bias and effect size was found to be linear in nature, such that as the risk of bias decreased so too did the effect size

Length of treatment was not found to correlate with treatment efficacy.

Risk of publication bias

Tests for the presence of publication bias suggested that some studies were missing from publication

Statistical measures to take account of these putative ‘missing studies’ decreased the effect size at post-test analysis to a ‘small effect’, although the finding remained statistically significant (g=0.23 95% CI 0.07 to 0.38). However, statistical significance was lost at the follow up point of analysis (g = 0.19 95% CI -0.15 to 0.53) when ‘missing’ studies were included in the analysis.

DBT and psychodynamic therapy approaches were found to be effective versus control, CBT and other treatment types were not.

Discussion

The authors concluded:

Psychotherapies, most notably dialectical behaviour therapy and psychodynamic approaches, are effective for borderline symptoms and related problems. Nonetheless, effects are small, inflated by risk of bias and publication bias, and particularly unstable at follow-up.

As the authors of an accompanying editorial (Fonagy et al., 2017), addressing the findings of this systematic review, comment: the findings of a small to moderate effect size, that is maintained at follow up is reassuring, and indicates that the long standing myth of BPD being ‘untreatable’ is now difficult to sustain.

As for all systematic reviews, the current study has some inherent limitations, specifically relating to the level of abstraction necessary to handle the amount of included data in a robust manner. For example, the accompanying editorial questions the combination of varying treatment modalities, with different therapeutic processes under the heading of ‘psychodynamic therapies.’

However, the study also raises some important points for consideration in future research. For example, as the authors suggest, the findings that treatment efficacy is not maintained in comparison with control group interventions when study team members are involved in the treatment of the control group, or when a manualised control intervention is used, perhaps indicate that there is some specific benefit from the ‘focus’ or structured nature of these different states that benefits people with experiences of distress associated with BPD. Furthermore, the lack of an association between length of treatment and outcome also indicates a need for exploration regarding cost effectiveness, or the ‘necessary components’ for therapeutic efficacy.

High quality, structured reviews, such as this one, are significant not only for the findings they themselves demonstrate, but also for the avenues of enquiry that they open up.

The long-standing myth that borderline personality disorder is untreatable is now difficult to sustain.

Following completing his PhD Andrew has recently returned to full time clinical practice and is currently trying to acclimatise to life back within the NHS... He maintains his research interests and will take up a clinical lectureship post from February.

Hi Andrew, Thanks for another cracking blog. Did you come across discussion/data which clearly defined and characterised robust diagnosis of BPD in the studies included? I am wondering if the same criteria were used in all studies and if not what impact would this have on the data they evaluate?

I have a severe former of bed and have not yet found anything that is of use other than medic as toon. I was diagnosed in 2012 following years of bullying in the workplace. I have severe bouts of suicidal ideation and small going through one now. I have attempted suicide 8 times so far. I self harm but in between, I try so so hard to keep from getting overwhelmed by things but it usually only lasts a few months and even that is really hard. I feel like I have been dealt a death card. I did have a very rough up bringing with two very abusive patents. I was serially abused at 8yrs by a family in law, I was in a bombing at age 7yrs and witnessed too much for a seven year old and I was raped at age 27yrs. I got through all of that…managed to do very well work we use and horse rode competitively, was very fit, very social, had lots of friends despite everything that had happened. Then shenanigans the bullying started in 2010 I thoughthink I could cope but 2 yes on I was struggling and reached rock bottom..I had planned you take my own life…I reported the bullying to management and that was the worst thing I could have fine, I had to kiss my job goodbye. The company refused to believe me even though I had proof. Since losing my job of 15 yes, a job I loved and excelled at I gave been unable to pull myself back up. I feel I have lost myself. I can’t remember what it was like to really enjoy life. Each day I just wish it would end….